The present invention is related to a flexible thin membrane reflector such as can be used for telescopes or radiation antennas. The thin membrane reflector of this invention can be built for lower cost and less weight than reflectors of traditional design with glass mirror surfaces for instance and additionally is particularly adaptable to active figure control
Thin membrane reflectors which are electrostatically controlled are known in the prior art. The concept of deforming a thin membrane into a curved reflecting surface by using electrostatic forces is old. One reflector taught in the prior art includes an electrode co-extensive in area with the free portion of a membrane and spaced in parallel relation to the membrane such that nearly a uniform attraction is exerted on the membrane. When a control voltage is applied, the membrane is deflected to a substantially spherical surface. Other than spherical surfaces can be obtained in this reflector system by choosing or selecting electrodes of different shapes, choosing different spacings or changing the control voltage.
However, a disadvantage of the thin membrane reflectors found in the prior art is the difficulty in dynamically controlling portions of the optical surface as they may deviate from the desired optical figure. In the thin membrane reflectors found in the prior art a single integral electrode is used to establish the electrostatic field which deflects the membrane. Consequently, control over selected portions of the membrane is not possible.